1. Field of the Invention
The present invention relates to a storage structure and method utilizing multiple protocol processor units and, more particularly, to a storage structure and method having multiple protocol processor units for a host bus adapter (HBA) of an internet small computer system interface (iSCSI).
2. Description of the Related Art
With improvements in the field of information technology, people are requiring with increasing frequency information devices; as a result, data storage requirements are also increasing, and consequently research into storage devices and related storage technologies are gaining importance. Data storage technologies include data storage methods, data management technologies, and connectivity technologies between the storage devices. Well known prior art storage technologies include redundant arrays of independent disks (RAID), network attached storage (NAS), small computer system interface (SCSI), storage area network (SAN), or fiber channel. A RAID is composed of a disk with a SCSI interface and a RAID control means. A NAS is a network storage apparatus composed of a SCSI disk or RAID disk array and a transmission protocol that takes files as a unit. The above-mentioned transmission protocol can be a network file system (NFS), or a common Internet file system (CIFS).
Since the Internet has become very important for people, network storage devices are getting more and more popular. The typical storage network is a network that connects a storage device to a server, and compared to technologies that directly connect the server and the storage devices together, such as a traditional RAID or SCSI connection, the storage network has higher transmission efficiencies, extensibility and reliability. Accordingly, a prior art internet small computer system interface (iSCSI) transmission protocol sends SCSI commands and data on an IP network using an iSCSI protocol data unit (PDU), and so the iSCSI protocol provides the IP network with storage network functionalities.
A user needs only to change the interface of the server and the storage device to an iSCSI interface to use an original IP network switching apparatus to establish a storage network. The current storage network transmission structure has two methods for increasing transmission speeds: one involves increasing the data processing speed of a protocol processing chip; another involves utilizing multiple protocol processing chips. The first method increases the transmission speed by enhancing the processing speed and has a simple structure. For example, the transmission speed of the chip of Ethernet physical layer increases from 1 GB/s (1 Gigabyte/second) to 10 GB/s (10 Gigabytes/second); however, this requires consideration of the design of the unit because not all designs are easy to modify so as to increase their speeds. Usually, more complicated units are more difficult to design for increased speeds, especially complicated protocol processing chips. Therefore, the first method is limited by acceleration limitations of the chip.
The other method utilizes multiple protocol processing chips to increase the transmission speed. The simple protocol processing unit, such as in the medium access control (MAC) layer or the physical (PHY) layer, can be designed by enhancing the processing speed. On the other hand, a complicated unit can be designed with multiple processing chips using, for example, transmission control protocol/internet protocol (TCP/IP) offload engines and iSCSI processors.
Therefore, it is desirable to provide a storage structure and method having multiple protocol processor units to mitigate and/or obviate the aforementioned problems.